Outcome In Pancreatic Ductal Adenocarcinoma Research Articles

Exogenous or in situ vaccination to trigger clinical responses in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease for which remarkable therapeutic resistance is the norm. Conventional immunotherapies, like immune checkpoint inhibitors, show limited efficacy in PDA due to a remarkably immunosuppressive tumor microenvironment (TME) and systemic inflammation. This review discusses the potential of both exogenous and in situ vaccination strategies to overcome these barriers and enhance anti-tumor immunity in PDA. Exogenous vaccines, including whole-cell, dendritic cell, peptide, and nucleic acid-based vaccines, have shown varying degrees of promise but face challenges related to antigen selection, production complexities, and patient-specific factors. In contrast, in situ vaccination strategies leverage conventional cytotoxic therapies, such as chemotherapy and radiation therapy, to induce immunogenic cell death and modulate the TME with the aim to stimulate anti-tumor immunity. While preclinical studies support the use of in situ vaccination, balancing the stimulatory and inhibitory effects is likely fundamental to eliciting productive anti-tumor responses in patients. Ongoing research seeks to identify new innovative strategies that can harness the endogenous immune response and trigger in situ vaccination. Overall, while both vaccination approaches offer significant potential, further research and clinical trials will be needed to optimize these strategies for improving patient outcomes in PDA.

Promising biomarker panel to monitor therapeutic efficacy of neoadjuvant chemotherapy in pancreatic cancer patients.

Neoadjuvant chemotherapy (NAC) can provide improved survival outcomes in pancreatic ductal adenocarcinoma (PDAC) patients who respond to treatment, but currently available biomarkers cannot reliably predict NAC response. This study aimed to determine the potential of a previously identified diagnostic and prognostic biomarker panel (i.e. Ca-125, S100A2, S100A4, Mesothelin and Ca19-9) for the monitoring of NAC-response in PDAC patients. This single-centre, retrospective study, utilised serum from NAC treated PDAC patients to determine the levels of biomarkers by Enzyme-Linked Immunosorbent Assay (ELISA). The percentage of the tumour bed occupied by viable carcinoma (PVC) was used to divide patients into good (PVC < 50%) and poor (PVC ≥ 50%) NAC-responders. Statistical analysis was performed to measure the ability of individual biomarkers and a biomarker panel in NAC treatment response and patient survival. Serum specimens from a total of 108 PDAC patients were assessed. Ca-125, Ca19-9 and S100A2 showed a significant positive correlation with PVC. Ca-125 demonstrated a superior ability to monitor NAC treatment response (Area under receiver operating curve (AUC): .6954) compared to the more widely used clinical biomarker, Ca19-9 (AUC: .6291). A panel of Ca-125 and Ca19-9 showed good ability to monitor NAC response in PDAC patients (AUC: .7349). Patients with high levels of both Ca-125 and Ca19-9 were shown to have the poorest overall survival (median overall survival: 17 vs. 30 months). A serum biomarker panel of Ca-125 and Ca19-9 could be used for effective clinical management of PDAC patients undergoing NAC treatment.

Acute pancreatitis as an early sign of pancreatic cancer; a retrospective, matched cohort study

Background and aims Pancreatic ductal adenocarcinoma (PDAC) often presents as acute pancreatitis (AP). However, data on the clinical outcomes of PDAC initially presenting as AP are limited. We aimed to assess the clinical features of PDAC that manifest as AP. Methods We reviewed the PDAC database at the Asan Medical Center between 2010–2016. Our study included 77 patients with PDAC who presented with AP (PDAC-AP group) and 154 age-gender-matched PDAC patients as controls (PDAC-other group). Patients’ demographics, disease characteristics, and outcomes were compared between both groups. Results Acute pancreatitis was an initial symptom in 1.12% of the patients with PDAC (77 of 6,821). Approximately 81.8% of the patients had clinically mild pancreatitis, and 91% were diagnosed with PDAC within two months of presentation with AP. Main tumor size was significantly smaller in the PDAC-AP group than in the PDAC-other group (PDAC-AP: 2.59 ± 1.21 cm vs. PDAC-other: 3.73 ± 1.78 cm, p < 0.01). The PDAC-AP group patients were diagnosed earlier than those in the PDAC-other group (PDAC-AP: stage 1–2, 80.6% vs. PDAC-other: 46.7%, p < 0.01). The proportion of resectable PDAC was significantly higher in the PDAC-AP group (PDAC-AP: 64.9% vs. PDAC-other: 50%, p < 0.01). Overall survival was significantly longer in the PDAC-AP group than in the PDAC-other group (30.2 months vs. 19.9 months, p = 0.03). Conclusions In patients who presented with clinical AP, PDAC was identified at an earlier stage, and these patients showed better survival rates. These results suggest that AP may be an early sign of PDAC.

CALB2 drives pancreatic cancer metastasis through inflammatory reprogramming of the tumor microenvironment

BackgroundEarly dissemination to distant organs accounts for the dismal prognosis of patients with pancreatic ductal adenocarcinoma (PDAC). Chronic, dysregulated, persistent and unresolved inflammation provides a preferred tumor microenvironment (TME) for tumorigenesis, development, and metastasis. A better understanding of the key regulators that maintain inflammatory TME and the development of predictive biomarkers to identify patients who are most likely to benefit from specific inflammatory-targeted therapies is crucial for advancing personalized cancer treatment.MethodsThis study identified cell-specific expression of CALB2 in human PDAC through single-cell RNA sequencing analysis and assessed its clinicopathological correlations in tissue microarray using multi-color immunofluorescence. Co-culture systems containing cancer-associated fibroblasts (CAFs) and patient-derived organoids (PDOs) in vitro and in vivo were employed to elucidate the effects of CALB2-activated CAFs on PDAC malignancy. Furthermore, CUT&RUN assays, luciferase reporter assays, RNA sequencing, and gain- or loss-of-function assays were used to unravel the molecular mechanisms of CALB2-mediated inflammatory reprogramming and metastasis. Additionally, immunocompetent KPC organoid allograft models were constructed to evaluate CALB2-induced immunosuppression and PDAC metastasis, as well as the efficacy of inflammation-targeted therapy.ResultsCALB2 was highly expressed both in CAFs and cancer cells and correlated with an unfavorable prognosis and immunosuppressive TME in PDAC patients. CALB2 collaborated with hypoxia to activate an inflammatory fibroblast phenotype, which promoted PDAC cell migration and PDO growth in vitro and in vivo. In turn, CALB2-activated CAFs upregulated CALB2 expression in cancer cells through IL6-STAT3 signaling-mediated direct transcription. In cancer cells, CALB2 further activated Ca2+-CXCL14 inflammatory axis to facilitate PDAC metastatic outgrowth and immunosuppression. Genetic or pharmaceutical inhibition of CXCL14 significantly suppressed CALB2-mediated metastatic colonization of PDAC cells in vivo and extended mouse survival.ConclusionsThese findings identify CALB2 as a key regulator of inflammatory reprogramming to promote PDAC metastatic progression. Combination therapy with αCXCL14 monoclonal antibody and gemcitabine emerges as a promising strategy to suppress distant metastasis and improve survival outcomes in PDAC with CALB2 overexpression.

S85 Evaluating the Impact of Germline Testing and Next Generation Sequencing (NGS) on the Outcomes of Pancreatic Ductal Adenocarcinoma (PDAC): A Single Center Retrospective Outcomes Analysis Over 7 Years

S85 Evaluating the Impact of Germline Testing and Next Generation Sequencing (NGS) on the Outcomes of Pancreatic Ductal Adenocarcinoma (PDAC): A Single Center Retrospective Outcomes Analysis Over 7 Years

Abstract A014: Protein-informed gene methylation signatures to predict treatment response and outcomes in pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDA) is a deadly cancer with dismal outcomes. We need new biomarkers to optimize the limited treatment combinations used in current clinical practice. Many machine-learning models have been presented based on mutational or transcriptome data claiming to predict outcomes. Still, they do not provide actionable targets (genes) that could improve treatment response. Moreover, DNA-methylation changes that influence gene/protein expression have been explored for this purpose. From the literature, we curated a 122-gene panel (January 1970 to April 2024) constructed on the proteins with preclinical (on cell lines or mouse models) or clinical (tissue-based studies) evidence suggesting their individual roles in influencing response to drugs often used in managing PDA such as gemcitabine (Gem), nab-paclitaxel, oxaliplatin, 5-fluorouracil, irinotecan, and cisplatin. We hypothesized that methylation changes in these genes are surrogates for gene/protein expression and tested their clinical significance in The Cancer Genome Atlas (TCGA) PDA population (n=184). The goal was to develop methylation signatures composed of specific cytosines followed by guanine residue (CpG) sites that aid in identifying patients at high risk of treatment failure and poor outcomes. We used elastic net multivariate analysis to calculate survival and plot Kaplan Meier plots based on our gene panel. The alpha (α) used for this script was calculated based on the lowest mean error and the minimum lambda (λ) value accordingly for each iteration (100 iterations to calculate the best values for α and λ). Our analysis yielded 28 methylation signatures that could identify high-risk PDA patients with poor overall survival (OS). The number of CpG sites in these signatures ranged from 1 to 1933. The differences in OS for these signatures were better than those available in the literature. The best signature had 18 CpG sites (17 months (m) vs. not evaluable) followed by a 53-CpG site signature (16 m vs. 67m) and a 6-CpG site signature (17m vs. 67m). A signature with the highest CpG sites (1933) was not better than those with smaller ones (16m vs. 21m). Multiple signatures had &amp;gt;1 CpG sites from one gene. Early growth response 1 (EGR1) coding the KCNH2 gene has featured in most signatures. One CpG site in this gene had a clinically significant prognostic value (15m vs. 30m). Other frequently featured genes were CCDC85A, EGFR, SST, and HMGA1. The main drawbacks for this study were that Gem-related genes (&amp;gt; 60) dominated the panel, and those with Gem treatment dominated the patient population. This panel should be further refined to make it more relevant to current clinical practice. We provide preliminary evidence suggesting the clinical significance of our panel and lay the foundation for future studies that would enable us to personalize prognostication and treatment selection in PDA patients. Our work can provide novel therapeutic targets that, alone or in combination with chemotherapy, can improve the outcomes for PDA. Citation Format: Ashish Manne, Harshitha Puram, Deepak Sherpally, Sravan Jeepalyam, Upender Manne. Protein-informed gene methylation signatures to predict treatment response and outcomes in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A014.

Aronia Berry Extract Modulates MYD88/NF-kB/P-Glycoprotein Axis to Overcome Gemcitabine Resistance in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with poor survival rates, primarily due to the limited effectiveness of gemcitabine (Gem)-based chemotherapy, as well as the acquisition of chemotherapeutic resistance. Aronia berry extracts (ABEs), abundant in phenolic constituents, have been recently recognized for their anticancer properties as well as their encouraging potential to help overcome chemoresistance in various cancers. In the present study, we explored ABE's potential to overcome Gem resistance in PDAC and identify specific growth regulatory pathways responsible for its anticancer activity. Through a series of in vitro experiments in gemcitabine-resistant (Gem-R) cells, we elucidated the synergistic interactions between Gem and ABE treatments. Using advanced transcriptomic analysis and network pharmacology, we revealed key molecular pathways linked to chemoresistance and potential therapeutic targets of ABE in Gem-R PDAC cells. Subsequently, the findings from cell culture studies were validated in patient-derived 3D tumor organoids (PDOs). The combination treatment of ABE and Gem demonstrated significant synergism and anticancer effects on cell viability, proliferation, migration, and invasion in Gem-R cells. Transcriptomic analysis revealed a correlation between the NF-Κb signaling pathway and Gem-R (p < 0.05), exhibiting a marked upregulation of MYD88. Additionally, MYD88 exhibited a significant correlation with the overall survival rates in patients with PDAC patients in the TCGA cohort (HR = 1.58, p < 0.05). The MYD88/NF-Κb pathway contributes to chemoresistance by potentially upregulating efflux transporters like P-glycoprotein (P-gp). Our findings revealed that the combined treatment with ABE suppressed the NF-Κb pathway by targeting MYD88 and reducing P-gp expression to overcome Gem resistance. Lastly, the combination therapy proved highly effective in PDOs in reducing both their number and size (p < 0.05). Our study offers previously unrecognized insights into the ability of ABE to overcome Gem resistance in PDAC cells through its targeting of the MYD88/NF-κb/P-gp axis, hence providing a safe and cost-effective adjunctive therapeutic strategy to improve treatment outcomes in PDAC.

Co‑expression of SLC20A1 and ALDH1A3 is associated with poor prognosis, and SLC20A1 is required for the survival of ALDH1‑positive pancreatic cancer stem cells.

Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter, which has been identified as a prognostic marker in several types of cancer, including pancreatic cancer. However, to the best of our knowledge, the association between SLC20A1 expression and cancer stem cell (CSC) markers, such as aldehyde dehydrogenase 1 (ALDH1), in pancreatic ductal adenocarcinoma (PDAC), and the role of SLC20A1 in PDAC CSCs remains unclear. In the present study, a genomic dataset of primary pancreatic cancer (The Cancer Genome Atlas, Pan-Cancer Atlas) was downloaded and analyzed. Kaplan-Meier analysis and multivariate Cox regression analysis were performed to evaluate the overall survival, disease-specific survival (DSS), disease-free interval (DFI) and progression-free interval (PFI). Subsequently, SLC20A1 small interfering RNA (siRNA) knockdown (KD) was induced in the PANC-1 and MIA-PaCa-2 PDAC cell lines, and in sorted high ALDH1 activity (ALDH1high) cells, after which, cell viability, in vitro tumor sphere formation, cell death and caspase-3 activity were examined. The results revealed that patients with high expression of SLC20A1 (SLC20A1 high) at tumor stage I had a poor prognosis compared with patients with low expression of SLC20A1 (SLC20A1 low) in terms of DSS, DFI and PFI. In addition, patients with high expression of SLC20A1 and ALDH1A3 (SLC20A1 high ALDH1A3 high) exhibited poorer clinical outcomes than patients with high expression of SLC20A1 and low expression of ALDH1A3 (SLC20A1 high ALDH1A3 low), low expression of SLC20A1 and high expression of ALDH1A3 (SLC20A1 low ALDH1A3 high) and SLC20A1 low ALDH1A3 low. SLC20A1 siRNA KD in ALDH1high cells isolated from PANC-1 and MIA-PaCa-2 cell lines resulted in suppression of in vitro tumorsphere formation, and enhancement of cell death and caspase-3 activity. These results suggested that SLC20A1 was involved in cell survival via the suppression of caspase-3-dependent apoptosis, and contributed to cancer progression and poor clinical outcomes in PDAC. In conclusion, SLC20A1 may be used as a prognostic marker and novel therapeutic target of ALDH1-positive pancreatic CSCs.

Genetic ancestry-associated differences in genomic profiling and treatment patterns in pancreatic ductal adenocarcinoma (PDAC).

4138 Background: Prior epidemiological studies have explored race both as a population-level risk factor and as a factor influencing outcomes in PDAC. However, the impact of genetic ancestry on PDAC remains unclear. We assessed the genomic landscape, clinical care patterns, and outcomes across ancestries in a large and diverse PDAC cohort to determine the potential impact of genomics on ancestral disparities. Methods: A total of 24,948 patients diagnosed with PDAC who received tissue-biopsy based comprehensive genomic profiling (CGP; Foundation Medicine, Inc. (FMI)) as part of routine clinical care from Aug 2014-Sep 2023 were examined for genomic differences based on genetic ancestry which was determined using a SNP-based approach. The US-based de-identified Flatiron Health (FH)-FMI clinico-genomic database (CGDB) was used to assess testing and treatment patterns based on ancestry in 3,863 patients of European (EUR) and 414 patients of African (AFR) ancestry diagnosed with PDAC. Results: The genetic ancestry distribution in the overall cohort was 80.9% EUR, 10.0% AFR, 4.9% Admixed American, 3.5% East Asian, and 0.7% South Asian. AFR patients showed a slightly younger median age at biopsy than EUR (64 vs 67, p &lt; .001). KRAS, TP53, CDKN2A/ 2B and SMAD4 were the most commonly altered genes in the cohort, as expected. Compared to EUR, AFR patients were enriched in alterations in TP53 (85% vs 78%, p &lt; .001) and KRAS (95% vs 93%, p &lt; .001). While rare, alterations in GNAS, CHEK2, and BRAF were observed less frequently in AFR (1.7% vs 3.3%, 0.3% vs 1.7%, 0.9% vs 2.2%, respectively, all p &lt; .001). In the CGDB cohort, AFR patients were likely to have lower socioeconomic status (SES) compared to EUR patients (33% of AFR in the lowest SES quintile compared to 9% of EUR; p &lt; .001 across all quintiles). AFR patients were less likely to receive care at academic centers (AFR 14.8% vs EUR 22.2%, p &lt; .001) and less likely to receive an investigational drug during their cancer treatment course (5.9% vs 14.1%, p = .001). Rates of surgery (AFR 30.2% vs EUR 34.6%, p = .08), immunotherapy (3.2% vs 3.3%, p &gt; .99), and targeted therapy (4.1% vs 6.2%, p = .28) were not significantly different. While AFR patients comprised a significantly larger proportion of AFR+EUR CGP volume following the decision to implement Medicare coverage for NGS testing (10.6% after Mar 16, 2018 vs 6.6% prior, p &lt; .001), this remained below the expected based on share of the overall US population. Conclusions: To our knowledge, this is the largest study of genetic ancestry in PDAC to date. There were largely similar patterns of gene alterations across AFR and EUR ancestry groups suggesting non-genomic factors may underlie clinical outcomes disparities which have been reported in other studies. Notably, there were ancestry-based differences associated with SES and both CGP testing and clinical trial enrollment patterns, which may impact patient outcomes.

Targeting Neoantigens in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is currently the third leading cause of cancer-related death in the United States after lung and colon cancer. PDAC is estimated to be the second leading cause of cancer-related death by 2030. The diagnosis at a late stage is the underlying cause for higher mortality and poor prognosis after surgery. Treatment resistance to chemotherapy and immunotherapy results in recurrence after surgery and poor prognosis. Neoantigen burden and CD8+ T-cell infiltration are associated with clinical outcomes in PDAC and paucity of neoantigen-reactive tumor-infiltrating lymphocytes may be the underlying cause for treatment resistance for immunotherapy. This suggests a need to identify additional neoantigens and therapies targeting these neoantigens to improve clinical outcomes in PDAC. In this review, we focus on describing the pathophysiology, current treatment strategies, and treatment resistance in PDAC followed by the need to target neoantigens in PDAC.

Pancreatic cancer: new approaches to drug therapy.

Outcomes in pancreatic ductal adenocarcinoma (PDAC) remain poor due to a variety of biological, clinical, and societal factors. However, in recent years, PDAC has seen 1) increased precision of initial evaluation, 2) increased emphasis on supportive care, 3) deeper understanding of the translation biology of PDAC, especially as pertains to genomic alterations, and 4) foundational combination chemotherapy clinical trials across all disease stages. These advances have led to a wide range of new approaches to drug therapy for PDAC. Currently available drugs are showing added benefit, both by resequencing them with each other and also with respect to other therapeutic modalities. Molecular strategies are being developed to predict response to known therapeutic agents and to identify others. Additionally, a wide range of new drugs for PDAC are under development, including drugs which inhibit critical molecular pathways, drugs which attempt to capitalize on homologous repair deficiencies, immunotherapeutic approaches, antimetabolic agents, and drugs which attack the extracellular matrix which supports PDAC growth. These new approaches offer the promise of improved survival for future PDAC patients.

Development of Clinical Radiomics-Based Models to Predict Survival Outcome in Pancreatic Ductal Adenocarcinoma: A Multicenter Retrospective Study.

This multicenter retrospective study aims to identify reliable clinical and radiomic features to build machine learning models that predict progression-free survival (PFS) and overall survival (OS) in pancreatic ductal adenocarcinoma (PDAC) patients. Between 2010 and 2020 pre-treatment contrast-enhanced CT scans of 287 pathology-confirmed PDAC patients from two sites of the Hopital Universitaire de Bruxelles (HUB) and from 47 hospitals within the HUB network were retrospectively analysed. Demographic, clinical, and survival data were also collected. Gross tumour volume (GTV) and non-tumoral pancreas (RPV) were semi-manually segmented and radiomics features were extracted. Patients from two HUB sites comprised the training dataset, while those from the remaining 47 hospitals of the HUB network constituted the testing dataset. A three-step method was used for feature selection. Based on the GradientBoostingSurvivalAnalysis classifier, different machine learning models were trained and tested to predict OS and PFS. Model performances were assessed using the C-index and Kaplan-Meier curves. SHAP analysis was applied to allow for post hoc interpretability. A total of 107 radiomics features were extracted from each of the GTV and RPV. Fourteen subgroups of features were selected: clinical, GTV, RPV, clinical & GTV, clinical & GTV & RPV, GTV-volume and RPV-volume both for OS and PFS. Subsequently, 14 Gradient Boosting Survival Analysis models were trained and tested. In the testing dataset, the clinical & GTV model demonstrated the highest performance for OS (C-index: 0.72) among all other models, while for PFS, the clinical model exhibited a superior performance (C-index: 0.70). An integrated approach, combining clinical and radiomics features, excels in predicting OS, whereas clinical features demonstrate strong performance in PFS prediction.

Postoperative long‑term outcomes of acute normovolemic hemodilution in pancreatic cancer: A propensity score matching analysis.

Acute normovolemic hemodilution (ANH) is a useful intraoperative blood conservation technique. However, the impact on long-term outcomes in pancreatic ductal adenocarcinoma (PDAC) remains unclear. The present study investigated the impact of ANH on long-term outcomes in patients with PDAC undergoing radical surgery. Data from 155 resectable PDAC cases were collected. Patients were categorized according to whether or not they had received intraoperative allogeneic blood transfusion (ABT) or ANH. Postoperative complications, recurrence-free survival (RFS) and disease-specific survival (DSS), before and after propensity score matching (PSM), were compared among patients who did and did not receive ANH. A total of 44 patients (28.4%) were included in the ANH group and 30 patients (19.4%) were included in the ABT group; 81 (52.3%) patients, comprising the standard management (STD) group, received neither ANH nor ABT. The ABT group had the worst prognosis among them. Before PSM, ANH was significantly associated with decreased RFS (P=0.043) and DSS (P=0.029) compared with the STD group before applying Bonferroni correction; however, no significant difference was observed after applying Bonferroni correction. Cox regression analysis identified ANH as an independent prognostic factor for RFS [relative risk (RR), 1.696; P=0.019] and DSS (RR, 1.876; P=0.009). After PSM, the ANH group exhibited less favorable RFS [median survival time (MST), 12.1 vs. 18.1 months; P=0.097] and DSS (MST, 32.1 vs. 50.5 months; P=0.097) compared with the STD group; however, these differences were not statistically significant. In conclusion, while ANH was not as harmful as ABT, it exhibited potentially more negative effects on long-term postoperative outcomes in PDAC than STD.

Abstract 6313: Enhancing CAR T cell-based immunotherapy outcomes in PDAC: Evaluating iC9.B7-H3 CAR T cells in adjuvant, neoadjuvant, and monotherapy settings

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is among the most aggressive and lethal cancers worldwide. Despite negative margin resections and subsequent systemic therapy, PDAC often recurs. Additionally, most patients present with locally advanced and unresectable tumors at the time of diagnosis. Cancer-associated fibroblasts (CAFs) contribute to the highly desmoplastic tumor microenvironment (TME) and form a biophysical barrier, limiting immune cell infiltration. Moreover, CAF-secreted factors suppress the anti-tumor activity of T cells and shift cancer cells toward invasive proliferative and mesenchymal phenotypes. Therefore, targeting CAFs can enhance T-cell infiltration and improve the efficacy of T-cell based immunotherapeutic strategies. B7-H3 is an immune checkpoint molecule highly expressed on PDAC cells and CAFs. In this study, we investigate the use of Chimeric Antigen Receptor (CAR) T cells targeting B7-H3 to eliminate metastatic PDAC in a preclinical mouse model in three different settings: I. Adjuvant II. Neoadjuvant III. CAR T cell monotherapy. Our CART-B7-H3 construct includes an inducible caspase 9 (iC9) suicide gene, which allows for the controlled elimination of the CAR T cells in the event of overwhelming cytokine release syndrome. Methods: To validate the therapeutic potential of iC9.B7-H3 CAR T cells in vivo, NSG mice were orthotopically engrafted with 1x105 patient-derived PDAC6 cells and 9x105 hCAF1 cells at a ratio of 1:9, reflecting a clinically relevant model. In the adjuvant group, mice underwent surgical resection of the primary tumor (distal pancreatectomy and splenectomy) after 25 days. On days 30 and 60, they received systemic iC9.B7-H3 CAR T cell treatment (5x106). In the neoadjuvant group, mice were systemically treated with iC9.B7-H3 CAR T cells on day 19 and underwent surgical resection of the primary tumor on day 25, following another systemic CAR T cell dose on day 60. In the CAR T monotherapy group, mice received systemic iC9.B7-H3 CAR T cells on days 19 and 60. Results: In vivo, iC9.B7-H3 CAR T cells in the neoadjuvant group effectively eradicated both local and distant PDAC metastases for the length of the experiment (180 days) and significantly increased the survival (P &amp;lt;0.0001), indicating long-term efficacy in the treatment of PDAC metastases with no adverse side effects. In the adjuvant and CAR T monotherapy groups, iC9.B7-H3 CAR T cells effectively control tumor growth, eliminate metastases, and significantly increase survival (P=0.0018 and P=0.0007, respectively). Conclusion: These data suggest that the neoadjuvant application of iC9.B7-H3 CAR T cells may demonstrate persistent efficacy in eradicating both local and distant PDAC metastases. iC9.B7-H3 CAR T cells adjuvantly and as monotherapy achieved significant tumor control. Citation Format: Shahrzad Arya, Seyed Amir Sanatkar, Marco Ventin, Giulia Cattaneo, Cristina Martin, Gabriella Lionetto, Jingyu Jia, Feng Chen, David T. Ting, Xinhui Wang, Sandra Ryeom, Cristina R. Ferrone, Soldano Ferrone. Enhancing CAR T cell-based immunotherapy outcomes in PDAC: Evaluating iC9.B7-H3 CAR T cells in adjuvant, neoadjuvant, and monotherapy settings [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6313.

Abstract 5893: Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma

Abstract In recent years, a growing body of research has illuminated the integral role of the nervous system in the initiation and progression of cancer, giving rise to the establishment of an emergent field known as cancer neuroscience. Pancreatic ductal adenocarcinoma (PDAC), constituting 90% of pancreatic cancers, manifests as a highly malignant solid tumor characterized by insidious onset, strong invasiveness, and a notable propensity for recurrence or metastasis. Consequently, the 5-year survival rate for PDAC remained dismally low at approximately 10% in 2021. Notably, PDAC is distinguished by perineural invasion (PNI), a phenomenon linked to postoperative recurrence and metastasis. A thorough exploration of the interplay between peripheral innervation and PDAC holds promise for identifying novel targets and therapies to enhance outcomes in PDAC. This study unveils a correlation between PDAC patients exhibiting high calcitonin gene-related peptide-positive (CGRP+) sensory innervation in the tumor microenvironment (TME) and diminished overall survival (OS) and disease-free survival (DFS) compared to those with lower CGRP+ nociceptive innervation. Concurrently, heightened CGRP+ sensory innervation corresponds to increased cancer pain, as assessed by Visual Analog Scale (VAS) scores. Further analysis reveals a negative association between CGRP+ nociceptive nerves and lymphatic metastasis, as well as tumor size in PDAC patients. In a murine PDAC model, the genetic or chemical ablation of CGRP+ sensory neurons significantly impedes disease progression. Additionally, sensory neuron ablation attenuates cancer-induced vesical pain and enhances the locomotor function of mice, suggesting an improvement in overall quality of life. Mechanically, within the TME of PDAC, the secretion of neuropeptides substance P (SP) and CGRP from sensory neurons is elevated, with CGRP exhibiting a more pronounced increase. Furthermore, the expression of the CGRP receptor—receptor activity modifying protein 1 (RAMP1)—surpasses that of the SP receptor in the TME. Subsequent blockade of the CGRP pathway using the RAMP1 antagonist Rimegepant significantly suppresses PDAC progression and alleviates cancer pain, accompanied by improved locomotor function. In summary, sensory innervation actively participates in the progression of PDAC through the secretion of CGRP. Consequently, the inhibition of the CGRP pathway emerges as a potential therapeutic strategy for both PDAC and cancer-induced pain. Citation Format: Kaiyuan Wang, Bo Ni, Xiuchao Wang, Jihui Hao. Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5893.

Abstract 7615: Epithelial-mesenchymal-transition gene signature changes and poor oncological outcome in Candida-positive pancreatic ductal adenocarcinoma

Abstract Candida are commonly found in bile collected during surgery in pancreatic ductal adenocarcinoma (PDAC) patients. However, their significance in tumor biology and oncological outcome is unclear. PDAC patients receiving neoadjuvant therapy and pancreatectomy with intraoperative bile fungal culture were identified (N=40) in a prospective single-institution cohort. Tumor regression scores (TRS) were abstracted from pathology reports and correlated with bile fungal cultures. Bulk tumor RNASeq data were obtained from the Oncology Research Information Exchange Network (ORIEN). Tumor microbiome data of non-metastatic PDAC patients with upfront surgery were extracted using the {exotic} tool (Hoyd et al. Cancer Res. Commun., 2023). Gene expression profiles were compared between Candida+ and Candida- tumors, defined by a cutoff microbial count of 0. Overall survival (OS) of resected PDAC patients with Candida+ and Candida- tumors was compared using Kaplan Meier survival analysis. From the single-institution PDAC cohort, Candida+ bile was associated with poor pathological response to neoadjuvant therapy (Table 1). Using the ORIEN cohort, Candida were detected in 67% (106/158) of the PDAC tumors. Patients with Candida+ tumors had worse OS (median 28 vs. 56 months, Log-Rank p&amp;lt;0.008). Gene Set Enrichment Analysis (GSEA) using Hallmark gene sets showed an enrichment of epithelial-mesenchymal-transition (EMT) gene set and a reduction of metabolic and DNA repair gene sets in Candida+ tumors. GSEA for Immune signature and Tumor Immune Microenvironment Deconvolution (TIMEx) cell types showed an enrichment of Stromal-Fibroblast and EMT signature in Candida+ tumors. Further investigations are underway to determine the causal and metabolic relationship between Candida and this tumor microenvironment with EMT and stromal fibroblasts which is a well-known contributor to poor chemotherapy response and oncological outcome of PDAC. Table 1: Pathological Response to Neoadjuvant Therapy for PDAC Bile Culture TRS0/1 TRS2 TRS3 Candida - 5 (25%) 15 (75%) 0 (0%) Candida + 1 (5%) 11 (55%) 8 (40%) TRS: Tumor Regression Score (TRS0: complete response; TRS1: near-complete response; TRS2: partial response; TRS3: no response). Chi-Square Test, P=0.0035. Citation Format: Po Hien Ear, Min Hu, Jonathan S. Shilyansky, Naomi H. Fei, Sam Coleman, Rebecca Hoyd, Caroline E. Wheeler, Kelsey L. Steckly, Michelle L. Churchman, Nicholas Denko, Rebecca D. Dodd, Sheetal Hardikar, Ning Jin, Qin Ma, Martin D. McCarter, Abdul Rafeh Naqash, Afaf E. Osman, Gregory Riedlinger, Lary A. Robinson, Bryan P. Schneider, Eric A. Singer, Ahmad A. Tarhini, Gabriel Tinoco, Cornelia M. Ulrich, Yousef Zakharia, Daniel Spakowicz, Aik Choon Tan, Carlos H. Chan. Epithelial-mesenchymal-transition gene signature changes and poor oncological outcome in Candida-positive pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7615.

Circulating tumor-associated antigen-specific IFNγ+4-1BB+ CD8+ T cells as peripheral biomarkers of treatment outcomes in patients with pancreatic cancer.

CD8+ T cells affect the outcomes of pancreatic ductal adenocarcinoma (PDAC). Using tissue samples at pre-treatment to monitor the immune response is challenging, while blood samples are beneficial in overcoming this limitation. In this study, we measured peripheral antigen-specific CD8+ T cell responses against four different tumor-associated antigens (TAAs) in PDAC using flow cytometry and investigated their relationships with clinical features. We analyzed the optimal timing within the treatment course for effective immune checkpoint inhibition in vitro. We demonstrated that the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells was correlated with a fold reduction in CA19-9 before and after neoadjuvant therapy. Moreover, patients with TAA-specific IFNγ+4-1BB+ CD8+ T cells after surgery exhibited a significantly improved disease-free survival. Anti-PD-1 treatment in vitro increased the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells before neoadjuvant therapy in patients, suggesting the importance of the timing of anti-PD-1 inhibition during the treatment regimen. Our results indicate that peripheral immunophenotyping, combined with highly sensitive identification of TAA-specific responses in vitro as well as detailed CD8+ T cell subset profiling via ex vivo analysis, may serve as peripheral biomarkers to predict treatment outcomes and therapeutic efficacy of immunotherapy plus neoadjuvant chemotherapy.

Association of Mutant KRAS Alleles With Morphology and Clinical Outcomes in Pancreatic Ductal Adenocarcinoma.

Mutant KRAS is the main oncogenic driver in pancreatic ductal adenocarcinomas (PDACs). However, the clinical and phenotypic implications of harboring different mutant KRAS alleles remain poorly understood. To characterize the potential morphologic and clinical outcome differences in PDACs harboring distinct mutant KRAS alleles. Cohort 1 consisted of 127 primary conventional PDACs with no neoadjuvant therapy, excluding colloid/mucinous, adenosquamous, undifferentiated, and intraductal papillary mucinous neoplasm-associated carcinomas, for which an in-house 42-gene mutational panel had been performed. A morphologic classification system was devised wherein each tumor was assigned as conventional, papillary/large duct (P+LD, defined as neoplastic glands with papillary structure and/or with length ≥0.5 mm), or poorly differentiated (when the aforementioned component was 60% or more of the tumor). Cohort 2 was a cohort of 88 PDACs in The Cancer Genome Atlas, which were similarly analyzed. In both cohorts, there was significant enrichment of P+LD morphology in PDACs with KRAS G12V and G12R compared with G12D. In the entire combined cohort, Kaplan-Meier analyses showed longer overall survival (OS) with KRAS G12R as compared with G12D (median OS of 1255 versus 682 days, P = .03) and in patients whose PDACs displayed P+LD morphology as compared with conventional morphology (median OS of 1175 versus 684 days, P = .04). In the adjuvant-only subset, KRAS G12R had the longest OS compared with G12D, G12V, and other alleles (median OS unreached/undefined versus 1009, 1129, and 1222 days, respectively). PDACs with different mutant KRAS alleles are associated with distinct morphologies and clinical outcomes, with KRAS G12R allele associated with P+LD morphology and longer OS when compared with G12D using Kaplan-Meier studies.

Impact of KRAS mutations and co-mutations on clinical outcomes in pancreatic ductal adenocarcinoma

The relevance of KRAS mutation alleles to clinical outcome remains inconclusive in pancreatic adenocarcinoma (PDAC). We conducted a retrospective study of 803 patients with PDAC (42% with metastatic disease) at MD Anderson Cancer Center. Overall survival (OS) analysis demonstrated that KRAS mutation status and subtypes were prognostic (p < 0.001). Relative to patients with KRAS wildtype tumors (median OS 38 months), patients with KRASG12R had a similar OS (median 34 months), while patients with KRASQ61 and KRASG12D mutated tumors had shorter OS (median 20 months [HR: 1.9, 95% CI 1.2–3.0, p = 0.006] and 22 months [HR: 1.7, 95% CI 1.3–2.3, p < 0.001], respectively). There was enrichment of KRASG12D mutation in metastatic tumors (34% vs 24%, OR: 1.7, 95% CI 1.2–2.4, p = 0.001) and enrichment of KRASG12R in well and moderately differentiated tumors (14% vs 9%, OR: 1.7, 95% CI 1.05–2.99, p = 0.04). Similar findings were observed in the external validation cohort (PanCAN’s Know Your Tumor® dataset, n = 408).

The Role of Chemokines in Orchestrating the Immune Response to Pancreatic Ductal Adenocarcinoma

Chemokines are small molecules that function as chemotactic factors which regulate the migration, infiltration, and accumulation of immune cells. Here, we comprehensively assess the structural and functional role of chemokines, examine the effects of chemokines that are present in the pancreatic ductal adenocarcinoma (PDAC) tumor microenvironment (TME), specifically those produced by cancer cells and stromal components, and evaluate their impact on immune cell trafficking, both in promoting and suppressing anti-tumor responses. We further explore the impact of chemokines on patient outcomes in PDAC and their role in the context of immunotherapy treatments, and review clinical trials that have targeted chemokine receptors and ligands in the treatment of PDAC. Lastly, we highlight potential strategies that can be utilized to harness chemokines in order to increase cytotoxic immune cell infiltration and the anti-tumor effects of immunotherapy.